Rotor and stirring device

Abstract

The present invention relates to a rotor that comprises a series of shaped rotor blades whose circumferential section forms a standard NACA four-digit airfoil. Said rotor can be inserted in a stirring device that also comprises a stator, on whose inner surface shaped stator blades are positioned, whose circumferential section forms a standard NACA four-digit airfoil.

The invention claimed is: 
     
       1. A rotor which includes a shaft, a series of shaped rotor blades arranged along the whole or part of the length of said shaft, said blades extending parallel to a plane orthogonal to a rotational axis of said shaft; said series of shaped rotor blades contains at least one level of shaped rotor blades; each level contains at least two shaped rotor blades equally spaced about said shaft; said shaped rotor blades are connected to said shaft by means of one of their ends;
 a) wherein the shaped rotor blade comprises at least one reversal point of the thrust to the fluid, said reversal point divides said shaped rotor blade into at least two elements which extend radially with respect to one another, so that each element has a direction of thrust in the opposite direction with respect to the other, 
 b) wherein the circumferential section of each element forms a standard NACA four-digit airfoil shown as Digit 1, Digit 2, Digit 3 and Digit 4, in which:
 i. the parameters m, p, and t range radially along the direction of extension of the shaped rotor blade, 
 ii. the chord length c that connects the leading edge with the trailing edge of said profile varies radially along the direction of extension of the shaped rotor blade, 
 iii. the chord has an inclination a with respect to the orthogonal plane to the rotation axis that varies radially along the direction of extension of the shaped rotor blade. 
 
 
     
     
       2. The rotor according to  claim 1  in which m ranges between 0.001 and 0.25, p ranges between 0.01 to 0.85, t ranges between 0.015 and 0.75, the chord length c ranges between 0.02 and 0.25 times the rotor diameter D, and wherein the angle α of inclination of the chord ranges between 15° and 75° with the plane orthogonal to the rotation axis. 
     
     
       3. The rotor according to  claim 2  wherein the circumferential section of the shaped rotor blade in correspondence of the connection with the shaft forms said airfoil in which m ranges from 0.001 to 0.15, p ranges from 0.01 to 0.85, t ranges from 0.2 to 0.75, c ranges from 0.02 to 0.15, α ranges from 20° to 75°. 
     
     
       4. The rotor according to  claim 2  wherein the circumferential section of the shaped rotor blade in correspondence of the connection of the first element with the reversal point forms said airfoil in which m ranges from 0.001 to 0.25, p ranges from 0.01 to 0.7, t ranges from 0.2 to 0.65, c ranges from 0.02 to 0.2, α ranges from 15° to 60°. 
     
     
       5. The rotor according to  claim 2  wherein the circumferential section of the shaped rotor blade in correspondence of the connection of the second element with the reversal point forms said airfoil in which m ranges from 0.001 to 0.15, p ranges from 0.01 to 0.7, t ranges from 0.02 to 0.25, c ranges from 0.04 to 0.2, α ranges from 20° to 60°. 
     
     
       6. The rotor according to  claim 2  wherein the circumferential section of the shaped rotor blade in correspondence of the outer end of said blade form said airfoil in which m ranges from 0.001 to 0.25, p ranges from 0.01 to 0.75, t ranges from 0.015 to 0.25, c ranges from 0.04 to 0.25, α ranges from 15° to 45°. 
     
     
       7. The rotor according to  claim 1  wherein said airfoil of the shaped rotor blade is made with a curvilinear profile; or with a segmented continuous profile consisting of n segments in which two consecutive segments form an angle β, where n ranges between 2 and 10 and β ranges between 0.1° and 270°. 
     
     
       8. The rotor according to  claim 1  wherein said airfoil of the shaped rotor blade is realized with a continuous profile consisting of a combination of curvilinear sections and n segments in which two consecutive segments form an angle β which ranges between 0.1° and 270°, with n varying between 2 and 10. 
     
     
       9. A stirring device comprising:
 the rotor according to  claim 1 , which has the function of agitating a single-phase or multiphase fluid imparting motion, and 
 a stator that comprises an outer body and a series of shaped stator blades arranged on all or part of the inner side surface of said body; said series of shaped stator blades contains at least one level of shaped stator blades; each level contains at least two shaped stator blades equally spaced in the angular direction; the shaped stator blades are fixed to the inner side surface of said outer body by one of their ends, said stator having the function of transforming the motion generated by the rotor into predominantly axial flow. 
 
     
     
       10. A stirring device according to  claim 9  in which the shaped stator blade has the following features:
 the shaped stator blade includes at least one reversal point of the thrust to the fluid which divides it into at least two elements in such a way that each element has a direction of thrust in the opposite direction with respect to the other, 
 the circumferential section of each element forms a standard NACA four-digit airfoil, indicated as Digit 1, Digit 2, Digit 3 and Digit 4, in which: 
 i. the parameters m, p, t vary radially along the direction of extension of the shaped stator blade element, 
 ii. the chord length c that connects the leading edge with the trailing edge of said profile varies radially along the direction of extension of the stator blade shaped element, 
 iii. the chord has an inclination a with respect to the plane orthogonal to rotation axis which varies radially along the direction of extension of the shaped stator blade. 
 
     
     
       11. The device according to  claim 10  in which the circumferential section of the shaped stator blade forms said airfoil in which the parameter m ranges between 0.001 and 0.16, p ranges between 0.01 to 0.8, t ranges from 0.05 to 0.8, c ranges between 0.02 and 0.15 times the rotor diameter D, the angle α of inclination of the chord ranges between 25° and 80° relative to the plane orthogonal to rotation axis. 
     
     
       12. The device according to  claim 11  in which the circumferential section of the shaped stator blade in correspondence of the inner end of said blade forms said airfoil in which m ranges from 0.001 to 0.16, p ranges from 0.01 to 0.8, t ranges from 0.05 to 0.3, c ranges from 0.02 to 0.15, α ranges from 30° to 70°. 
     
     
       13. The device according to  claim 11  in which the circumferential section of the shaped stator blade in correspondence of the connection of the first element with the reversal point forms said airfoil in which m ranges from 0.001 to 0.15, p ranges from 0.01 to 0.75, t ranges from 0.15 to 0.6, c ranges from 0.02 to 0.15, α ranges from 40° to 80°. 
     
     
       14. The device according to  claim 11  in which the circumferential section of the shaped stator blade in correspondence of the connection of the second element with the reversal point forms said airfoil in which m ranges from 0.001 to 0.15, p ranges from 0.01 to 0.75, t ranges from 0.2 to 0.8, c ranges from 0.02 to 0.15, α ranges from 25° to 75°. 
     
     
       15. The device according to  claim 11  in which the circumferential section of the shaped stator blade in correspondence of the connection with the wall of the stator forms said airfoil in which m ranges from 0.001 to 0.15, p ranges from 0.01 to 0.75, t ranges from 0.2 to 0.8, c ranges from 0.02 to 0.15, α ranges from 25° to 75°. 
     
     
       16. The device according to  claim 10 , wherein said airfoil of the shaped stator blade is made with a curved profile; or with a continuous segmented profile consisting of n segments in which two consecutive segments form an angle β, where n ranges between 2 and 10 and β ranges between 0.1° and 270°. 
     
     
       17. The device according to  claim 10  wherein said airfoil of the shaped stator blade is realized with a continuous profile consisting of a combination of curvilinear and n segments in which two consecutive segments form an angle β which ranges between 0.1° and 270°, with n ranging between 2 and 10. 
     
     
       18. The device according to  claim 9  wherein the series of shaped rotor blades is between to the series of shaped stator blades so that it is the alternation of a level of shaped rotor and a level of shaped stator blades, forming a distance between shaped rotor blades and shaped stator blades that ranges from 5% to 100% of the height h of the shaped rotor blade. 
     
     
       19. The device according to  claim 9  wherein the shaped rotor blades and shaped stator blades are equally spaced in the angular direction. 
     
     
       20. The device according to  claim 10 , wherein the reversal point of the shaped stator blade or that of the shaped rotor blade, or both, is an element of shaped support whose distance from the rotation axis defines a circumference which divides the area generated transecting the stator into two areas of equal surface. 
     
     
       21. A method for preparing the airfoil shaped rotor blade of  claim 1  comprising: a) chips removal or welding together one or more forged or semi-finished bars or plates; or b) bending, twisting and bending bars and sheets, and then welding said bars and sheets between themselves in such a way as to approximate at best said airfoil. 
     
     
       22. A method for preparing the shaped stator blades of the stirring device of  claim 10  comprising: a) chips removal or welding together one or more forged or semi-finished bars or plates or b) bending, twisting and bending bars and sheets, and then welding said bars and sheets between themselves in such a way as to approximate at best said airfoil.